This invention relates to star-branched and comb-branched polyamides, star-branched and comb-branched polyamine derivatives thereof and to methods for their preparation.
Water-soluble polyamines and polyamides are known to be effective thickeners or viscosity modifiers for aqueous media. For example, acrylamide polymers and polyalkylenepolyamines such as polyethyleneimine have been employed extensively as thickeners for aqueous hydraulic fluids and fluid mobility control agents in secondary oil recovery. Hydrocarbon-soluble polyamides and polyamines have been used as viscosity modifiers and dispersants in lubricants. Unfortunately, however, such polymers often degrade when solutions of the polymers are subjected to a high degree of shear as is often the case in many applications for viscous aqueous fluids and hydrocarbon lubricants.
Therefore, it would be highly desirable to provide a polyamide and a polyamine derivative thereof which acts as a viscosity enhancer in aqueous and hydrocarbon fluids and which resists degradation upon exposure to high degrees of shear.